OK, I am not a developer or coder but was thinking that some future iteration could incorporate ground following without an elaborate sensor by using data. What if MP could include ground elevation data based on GPS position? That data should be available. If you limited it to a resolution of like one data point for each 20’x20’, you’d have about 750,000,000 data points for earth’s land mass. You wouldn’t need the oceans, just when GPS indicates over ocean ground height=0. Data requirements could be further reduced by only loading smaller subsets like country or state, etc.
The programming challenge would be to know what minimum resolution would be needed and how to program the flying dynamics to make smooth transitions. Also would need to consider odd situations like how fast to descend when flying over a cliff… and a “look-ahead” function to see when the bird is approaching a sheer vertical so it knows to increase altitude before making impact.
This sort of functionality would be helpful in hilly areas where the barometric sensor altitude could be referenced to real above ground altitude instead of just to launch point “flat earth” elevation.
Really? I guess I need to look into that. I thought you would need something like a downward looking LIDAR ground sensor. A data-based software solution would remove that hardware requirement. I’ll look into it some more, not that I have any urgent need for it. Just curious…
I’d think some type of sense and avoid is needed since altitude is the most inaccurate GPS vector, and with a sensor plus the GPS altitude data, your AP has a reasonable idea of what it can collide with… so it knows what it must avoid.
Back in the day, the Tomahawk cruise missile used an extensive terrain DB of a general operations area so it could perform nap of the earth flight without emitting any signals (like a radar). That works for that system.
For our micro-UAV’s, we will need sense and avoid real soon if we want to fly over any living persons or highways. I see guys flying flight plans via Google earth and they are making some close flyby of obstructions and powerlines. The FAA is aware of these flights, and are hoping the UAV work at NASA-Ames produces the algorithms and open source code to raise the safety level of mUAVs weighing in the 3-15 pound range…ie, those that will be produced in HUGE numbers and be flying close to the 300-400 foot altitude limit in controlled airspace. The code just needs to be small enough and safe enough to run on the PixHawk class of autopilots. (btw. Some autopilots are using NASA’s early sense & avoid system… so stay tuned)
